The invention relates to a machine table for a processing machine for holding at least one workpiece which is to be processed or at least one work accessory.
A workpiece of wood, for example, metal, plastic or glass can be fastened directly on such machine tables so that it can be worked by a processing machine, such as a router or the like. In addition, it is also possible to mount work accessories on the machine table, by means of which the workpiece, which is to be processed, is then held, or which, in turn, can be used to process the workpiece. For fastening the workpiece or a work accessory, suitable means are provided at the upper side of the machine table and interact with the workpiece or the work accessory, enabling the workpiece or work accessory to be clamped. Such means may comprise, for example, a groove-grid structure which is produced in the table surface and is connected with a source of vacuum so that a vacuum can be brought into the structure. By means of sealing cords inserted in the grooves, a bounded vacuum space can thus be created on which the workpiece is placed and thus held by suction. Instead of a groove grid structure, it is also possible to provide vacuum channels which discharge at the upper side and are also connected to a source of vacuum and can be sealed by suitable sealing elements. If a workpiece or a work accessory is to be clamped, the necessary openings are simply opened, so that the vacuum can be applied to the workpiece or work accessory. Moreover, magnetic surfaces are also known on which work accessories which have a metallic holding section can be placed and held. These are only some of the known clamping techniques which can be used in order to be able to hold workpieces or work accessories on a machine table. The list is not complete and other, appropriate clamping techniques are, of course known to those skilled in the art.
Each machine table is designed for a particular clamping technique, that is, the worker can use only one clamping technique at the table assigned to a processing machine. Consequently, when there is a change in the workpieces which are to be processed, for example, within the scope of a series production process, a device of the machine table, which is selected for workpiece A and on which, for example, appropriate work accessories in the form of vacuum suction elements are set down, which in their arrangement are placed in accordance with the shape of the workpiece A, must be changed in order to set up the table in accordance with the shape and the requirements of the workpiece B, which is to be processed subsequently. This is expensive and time consuming.
It is an object of the invention to provide a machine table which can be used more flexibly and variably.
Pursuant to the invention, this object is accomplished by a machine table having at least one table element which is mounted so that it can rotate about an axis and has at least two sides which can be brought into a working position by rotating the table element and at which the workpiece and/or the work accessory can be held.
The rotatability of the table element, which has at least two working sides at each of which a workpiece or a work accessory can be fastened, makes variable and very flexible working possible. At each side of the table, appropriate means for holding the workpiece or the work accessory, no matter of what type, are provided. Similar or different operating holding means can be provided at the respective sides. For the worker, there is the appreciable advantage that, for example, he can set up the first side of the table in accordance with a workpiece A having a first shape and the second or any additional side in accordance with the requirements of a further workpiece B, C, etc. which is to be processed. In the event that there is a change in workpieces, he need only rotate the table element so that the respectively set up working side faces upward. If, for example, in the case of a table element with two working sides, similar holding means in the form of a groove-grid structure, over which a vacuum can be applied to the workpiece, are provided on either side, then it is possible to use the sealing cord at a first side in accordance with the shape of workpiece A and to close off the vacuum channel openings which open up outside of the area surrounded by the sealing cords. At the opposite side, the sealing cord or cords can be placed in accordance with the shape of a workpiece B. In the event that there is a change in workpieces, an immediate change in the table side is possible, without having to undertake any other devices.
On the other hand, if different clamping techniques or different clamping means are realized at the sides, it is possible to clamp a workpiece A at the first side. If subsequently workpiece B is to be clamped and cannot be held with the clamping technique provided at the first side, the table element can be rotated and the second side with the other type of clamping technique, at which or by means of which the other workpiece B can be clamped, can be rotated to the top. Of course, the same applies also to mounting a work accessory. In this case, the machine table can be used for numerous functions by the worker in view of the possibility of clamping different types of workpieces with one and the same machine table using different clamping techniques or different holding means, and of processing these workpieces with one and the same processing machine. In the past, different combinations of machine tables and processing machines have always been required for this purpose, since the inventive variability of the clamping technique at one machine table did not exist.
Overall, the machine table in accordance with the invention offers the worker the possibility of working extremely rapidly and variably.
According to a first embodiment of the invention, the table element can be constructed as a tabletop with a large surface. In this embodiment, only one table element which is held at an appropriate table frame is used. It can be swiveled about an axis which, in the case of a conventional, rectangular construction of the tabletop, preferable extends in the longitudinal direction of the tabletop.
On the other hand, in embodiment of the invention, the table element is constructed in the form of a console, several console-like table elements, which are disposed parallel to one another, being provided at a table frame. In this embodiment of the invention, the table or clamping plane is formed by means of several table elements, which in each case have several sides which can be brought into an appropriate working position. A workpiece can be clamped at only one table element or, overlapping two or more table elements, clamped to these, either directly or with the insertion of appropriate work accessories, such as a vacuum suction apparatus or the like. Since each table element is mounted so that it can be rotated, turning in this way does not require much space and, at the same time, the possibility exists of forming very large table planes.
Moreover, each console-like table element can be essentially triangular at cross section and have three sides, at which appropriate holding means can be provided. In this manner, the worker can chose between three working sides. As an alternative to the triangular construction, each table element can be constructed essentially with a quadrilateral cross section and thus have four sides. Table elements with more than four sides are also conceivable.
Biangular, triangular or quadrilateral table elements are advantageous especially if, as can be provided pursuant to the invention, the console-like table elements are mounted displaceably at the table frame. The displaceable mounting offers the possibility that each table element can be positioned anywhere close to another table element, in order to be able, without any problems, to clamp also smaller workpieces which must be clamped using two table elements which are disposed next to one another. In addition, the possibility exists when using table elements with two sides, which then are essentially flat and rectangular, when using triangular table elements and when using quadrilateral table elements, to arrange these table elements so that they adjoin one another directly and form a closed table surface on which the workpiece can lie completely. The table elements themselves can be manually displaceable; additionally or alternatively, automatic displaceability may also be realized. For the automatic displacement, motorized or pneumatic driving mechanisms advisably are used. The automatic displacement advisably is controlled by a central control device. The table elements can be locked in the respective positions by suitable locking or fixing mechanisms. A shifting mechanism, which can be used, is described, for example, in German patent application No. DE 100 23 916, to which reference is explicitly made and the disclosure content of which is incorporated into the present application.
The turning of the table element or elements can also take place manually and/or automatically and appropriate motorized or pneumatic driving mechanisms can be provided, which are controlled over a common central control device. In the respective end position, the table elements are locked by suitable locking or fixing means. Moreover, several table elements can be rotated jointly by means of a joint motorized or pneumatic driving mechanism. Alternatively, the individual table elements can also be rotated separated by means of their own driving mechanism assigned to each table element.
As described above, similar or different acting means which engage the workpiece or the work accessory or interact with these can be provided at the sides for holding the workpiece and/or the work accessory. If more than two sides are provided at the respective table elements, that is, in the case of a triangular, quadrilateral or multilateral construction, it is, of course, possible to provide similar acting holding means at two or more sides and different acting holding means at the other sides, the concrete construction or distribution being immaterial here.
Moreover, the acting or holding means can be constructed directly at the respective side or be integrated there, that is, the means are permanently mounted at the respective side. However, to make the greatest possible flexibility feasible with respect to the means provided at a table element, it has proven to be particularly advantageous if at least one attachable element having or forming the respective means is or can be fastened at the respective side. In accordance with this embodiment of the invention, each table element is constructed in modular fashion inasmuch as it includes a basic support. One or more two-dimensional attachable elements can be fastened to the sides of the basic support. These attachable elements have or form the respective holding means, that is, with each attachable element, a specific clamping technique is realized or arranged at the basic support. This makes it possible, if necessary, to provide a desired clamping technique, which is not yet present at the respective table element, subsequently there, in exchange for a different one, for which purpose it is merely necessary to exchange attachable elements. With that, the machine table is even more variable and can be used even more flexibly by the worker.
Moreover, the acting or holding means of a first embodiment of the invention may comprise a grid-groove structure over which a vacuum is applied to the attached workpiece or work accessory. The grid-groove structure can be milled directly into the respective side of the table element or, alternatively, formed by a two-dimensional attachable element which in turn is fastened and preferably bolted to the support of the table element. A further embodiment of the holding means is in the form of a groove structure, especially a T-shaped groove structure, which interacts with corresponding counterpieces which can be introduced into the groove structure and are formed at the workpiece or work accessory for holding the workpiece. These preferably T-shaped grooves can be produced directly on the surface of the table element; alternatively, they may be formed in a holding plate. Work accessories, for example, in the form of separate clamping claws, a tailstock, a stop or the like are preferably held or clamped to such a holding structure. If such a structure is provided at a quadrilateral supporting element at right angles to a structure and clamping a workpiece by vacuum, then the vacuum clamping structure can be brought, for example, into the horizontal working position and appropriate stops can be fastened to the T-shaped groove structure, which extends perpendicularly thereto.
In another embodiment of the invention, the acting or holding means may comprise longitudinally extending rails on which at least one carriage carrying the workpiece or the work accessory can be shifted and locked. This carriage may, for example, carry a holding platform for a work accessory, such as vacuum clamping sleeves, which can be fastened, on the one hand, by vacuum to the flat holding platform and, on the other, clamp a workpiece at the top by vacuum. Vacuum clamping means, which can be used for this purpose, are described, for example, in German patent application No. DE 197 50 656, to which reference is explicitly made and the disclosure content of which is incorporated into the application. If the table element has a modular construction, then the rails are provided at an appropriate holding plate on which the carriage or carriages can then be placed.
In another embodiment relating to the holding means, the holding means may comprise a plurality of suction openings which can be closed off by valve elements and over which a vacuum can be applied to the workpiece or the work accessory which has been set down. These suction openings with the integrated valve elements can also be provided directly at the table element or at a suitable holding plate. An example of an embodiment of such a holding device is described, for example, in German patent application No. DE 100 23 323, to which reference is explicitly made and the disclosure content of which is incorporated into this application. Aside from the mechanical valve elements, described in this application, electrically operated valves can also be used which are controlled over a central control device. It is important here to ensure that the leads connecting the control device and the electrically operated valves cannot be sheared off when the table element is rotated.
Finally, according to another alternative of the holding means, the holding means comprise a magnetizable plate, especially a plate, which can be magnetized by electromagnets. Appropriate work accessories and, of course, also workpieces, which are to be processed and have an appropriate metal insert or the like, can also be held at the plate by these means.
In another embodiment of the invention, the holding means comprise a metal plate with a plurality of channel openings discharging into the top with assigned magnetic closing disks. A vacuum can be applied over the channel openings to the workpiece or work accessory. In this manner, the channel openings are closed by the closing disk and, if necessary, opened so that the worker can form any suction configuration simply by taking away the closing disks or setting them down.
In accordance with another embodiment of the invention, the holding means comprise a panel of wood or plastic, into which nails, screws or other elements can be introduced.
The respective attachable element is panel-shaped in order to realize the largest possible surface for accommodating the workpiece or work accessory along the table element. Each attachable element is fastened by suitable fastening means to the respective side of the table element, for which purpose fastening screws are preferably used and are screwed into corresponding threaded seats at the basic support. Each holding element forms an adaptor for a particular fastening or clamping technique.
For supplying the vacuum to the respective holding means which require a vacuum force, at least one vacuum channel is preferably provided within the table element. The means by which vacuum is supplied to the workpiece or work accessory can be supplied through this vacuum channel to which an external source of vacuum is connected. The channel itself is conducted so that appropriate openings are provided wherever vacuum is to be delivered to the workpiece. If the table element has a modular construction, it is preferable that several channel boreholes which communicate with the integrated vacuum channel and of which at least a portion can be connected with corresponding channel boreholes of the respective attachable elements, discharge at the respective side. The channel boreholes are arranged such that when a panel-shaped holding element is placed down, they are connected automatically with corresponding boreholes formed there in order to transfer the vacuum to the attachable element. In order to be able to couple the attachable element satisfactorily to the basic support of the channel boreholes provided at the basic support of the table, a corresponding channel network including a plurality of channel grooves may also be provided at the underside of the attachable element. If such a groove coincides with a corresponding channel borehole on the support, the entire channel network is automatically acted upon by vacuum. If an attachable element with a holding technique, which does not work with vacuum, is set down, the channel boreholes, which are provided in the support are simply sealed from the underside of the attachable element. Instead of a network of channels, a large vacuum cavity may also be provided at the underside of each attachable element. This means that the underside of the attachable element is somewhat removed from the upper side of the basic support. However, the edge of the attachable element itself is seated completely tight on the support.
Preferably, underneath each side of the table element, at least one vacuum channel is provided which discharges over channel boreholes at the respective side in order to create the possibility of mounting an attachable plate with vacuum holding means on any side.
According to a particularly advantageous embodiment of the invention, a vacuum channel assigned to one side can be connected with an external source of vacuum only in and automatically upon reaching the position in which the respective side is in its working position. If, in accordance with this embodiment, a side is rotated into its work position, the coupling of a vacuum channel assigned to the side with an external source of vacuum is realized automatically.
Furthermore, pursuant to the invention, one or more locking elements may be provided for locking the table element in the respective position. Locking bolts may be used which are controlled mechanically or electrically and engage corresponding locking recesses.
In view of the previously described automatic coupling of a vacuum channel with an external source of vacuum, it is particularly appropriate if at least one locking element is constructed simultaneously as a connecting element between the vacuum channel and the vacuum source, which can be connected to the locking element. Pursuant to this embodiment of the invention, an appropriately constructed locking element engages a vacuum channel when it snaps into the locking position and, at the same time, connects the vacuum channel with the source of vacuum. This locking element therefore has a locking as well as a channel-connecting function.
Since different work accessories are operated by compressed air, it is appropriate to provide at least one compressed air channel which can be connected with an external source of compressed air and is integrated in the table element and discharges at least at one side. This compressed air channel can also be tapped if the side at which it emerges is not in the upper working position. In this manner, the compressed air is supplied over a compressed air hose which can be connected to the work accessory, such as a clamping jaw which is fastened to the side in the working position.
A plate is preferably arranged at one side of the table element. Suitable means for connecting a vacuum channel or a compressed air channel the respective source and/or a locking element are provided at the plate and close off the vacuum channel or channels and optionally the compressed air channel or channels. The table element or a basic support itself is pressed preferably in the form of an extruded profile and consequently is open at both sides, where the basic support is closed off over appropriate closing plates and the corresponding channels are sealed preferably, all necessary connections are provided at this plate.
According to a further embodiment of the invention, each console-like table element includes several table element sections which are arranged in series and in each case have at least two sides which can be rotated separately about a common axis and can be mutually locked. The table element sections, which can be rotated and locked separately, can in turn carry any different clamping techniques at the respective sides, so that, within a table element plane, different clamping techniques at the different positions along the table element can be rotated into the working position so that the flexibility is increased even further. The table element sections can be rotated manually and/or mechanically. Locking is achieved with appropriate locking couplings, that is, the sections mutually interlock when they are in the appropriate end position, in which the respective sides of the sections extend parallel to one another.
In this embodiment, each table element section should have at least one vacuum channel and/or at least one compressed air channel. It should be possible to couple at least the channels of two adjacent table element sections which are in the upper working position with one another so that all operating means can be in communication with one another also between the table element sections over a central connection, as described above. Even though it is sufficient that in each case the channels in the sides in the working position can be coupled with one another, it is preferable that the channels of two adjacent table element sections which extend in the region of a side, not in the upper working position, can be coupled with one another in order to tap, for example, the compressed air from a side which is not rotated to the top and to supply it to a work accessory fastened at the upper side.
In view of providing a coupling of the channels which is as simple as possible, it is preferable if this coupling takes place automatically upon reaching a position in which the sides of two table element sections lie parallel to one another. This can be accomplished over suitable locking couplings, which enable the respective channels to be connected appropriately.
In additional embodiments of the invention, at least one table element section can be removed from the construction so that a modular system is realized in which the individual table element sections can be used alternately or removed. Moreover, the table element sections can be placed in a detachable manner on a central support extending in the axis of rotation and held there, for example, by screws, by being inserted or clamped or by a magnetic force. After the respective section is fastened, it can be rotated along by driving the support.
On the other hand, in another embodiment of the invention, each table element section can be removed completely from the construction so that there is a gap between two table element sections into which a third object can be inserted. In this embodiment of the invention, a third object, such as a workpiece to be processed, can be clamped between two table element sections and rotated so that it is possible to process the workpiece by turning, shaping, etc. The workpiece is delivered over one of the outer table elements while the table element at the other end forms the opposite side.
Further advantages, distinguishing features and details of the invention arise out of the examples, which are described in the following, and from the accompanying drawings.